FWIW......here is a better picture of the Muncie hole, different angle and lighting (from inside).
http://i1368.photobucket.com/albums/ag185/rsd1992/BetterMuncieHole_zps23eca19d.jpg
Here is a picture of the heater cutout, non-AC (from inside).
http://i1368.photobucket.com/albums/ag185/rsd1992/HeaterCutout_zps8c62486e.jpg
Thanks for all the great info!!!
Unfortunately, I don't have many of the original parts (no heater core, no fuel lines or tank, etc). Mostly just the body, steering wheel/box, subframe, and some interior parts. This is a running street car now (just), and wondering how I should proceed in the restore. If it's really rare (Z28), maybe worth it to do a full restore; if it's a SS/RS 350, just honor what it was....but don't get too crazy. Out of historical interest, I may try to find some of the previous owners. Maybe someone knows where the original parts are, or has some documentation.
http://i1368.photobucket.com/albums/ag185/rsd1992/BetterMuncieHole_zps23eca19d.jpg
Here is a picture of the heater cutout, non-AC (from inside).
http://i1368.photobucket.com/albums/ag185/rsd1992/HeaterCutout_zps8c62486e.jpg
Thanks for all the great info!!!
Unfortunately, I don't have many of the original parts (no heater core, no fuel lines or tank, etc). Mostly just the body, steering wheel/box, subframe, and some interior parts. This is a running street car now (just), and wondering how I should proceed in the restore. If it's really rare (Z28), maybe worth it to do a full restore; if it's a SS/RS 350, just honor what it was....but don't get too crazy. Out of historical interest, I may try to find some of the previous owners. Maybe someone knows where the original parts are, or has some documentation.

I've enclosed a picture of the plate, and a "pencil over-marking" for easier reading. Here is